1. Field of Invention
The invention relates to LED (light-emitting diode) lights and more particularly to a coin shaped light-emitting device including LEDs and a coin shaped spotlight comprising a plurality of light-emitting devices with improved characteristics including increased reliability, energy saving, and prolonged useful life.
2. Description of Related Art
Conventionally, a spotlight employs a halogen bulb which has the disadvantages of consuming energy and generating high temperature in use. Recently, LED lights are gaining popularity due to its advantageous features including low energy consumption and sufficient brightness. Thus, halogen lamps are gradually replaced by LED lights. There is a type of LED light as a spotlight commercially available. The LED bulb has the shape of a halogen bulb. As such, the LED light including the LED bulb is relatively large. Further, rails for mounting LED lights are required. Furthermore, the LED bulb has a narrow operating voltage. That is, voltage is required to be highly stable. Hence, the LED light cannot operate normally if an external source of power is not stable (i.e., large voltage variations). This has the disadvantages of shortening its useful life, etc.
Taiwanese Utility Model Patent No. M269,398 discloses a LED light comprising an array of a plurality of LEDs formed on a circuit board, a power supply circuit formed on a shell of the light, fin-shaped heat sinks, and a fan together for removing heat generated by the operating light.
While the Taiwanese Patent can emit highly bright light rays, it has disadvantages the same as that described in the above first paragraph. Thus, continuing improvements in the exploitation of LED light are constantly being sought.